WV: Command Serenity to carry the rope to you.

She is a tiny insect and cannot possibly lift more than the weight of a pumpkin seed!!!

She does however inform you of what the ledge contains through a series of informative blinks. There is an old rusty HARPOON lodged into the crumbling rock. Tied to it is a bunched-up jumble of HANDY CABLE. This strikes you as convenient! It is almost as if someone knew you would need a bunch of cable, and that you would have a MAYORAL SASH made out of cable, and that you were particularly attached to that MAYORAL SASH and would stubbornly refuse to use it.

Anyone who knew that much would surely possess a special gift! Alas it seems a bit far fetched.